Hitherto, as reinforcing materials for use in rubber composite materials for tires, there are known organic fiber cords and steel cords. In recent years, rubber composite materials comprising non-woven fabric have been proposed. For example, Japanese Patent Application Laid-Open No. 10-53010 proposes to dispose a rubber composite material comprising non-woven fabric between a carcass ply and a sidewall portion of a tire to increase the stiffness of sidewall portion and improve an operating stability of the tire without sacrificing its inherent properties such as comfortable ride and durability and without needing complicated production process.
Non-woven fabric has been noticed because of its good reinforcing capability, and the application of the non-woven fabric to rubber articles other than tire which are required to be stiff and durable has been recently studied. In conventional rubber composite materials containing no reinforcing material, it is also expected that the design freedom can be extended and a high durability can be achieved by using the non-woven fabric reinforcing material.
To exhibit excellent properties such as stiffness and elongation by using non-woven fabrics as the reinforcing materials for rubber composite materials, a sufficient impregnation of rubber into the inside of non-woven fabrics.
To remarkably improve durability by enhancing the stiffness of reinforced rubber articles, it is also known to increase the basis weight of non-woven fabrics. However, when the basis weight exceeds a certain level, the impregnation of rubber into the inside of non-woven fabric becomes lowered, resulting in failure to provide composite materials exhibiting a sufficient stiffness.
Conventionally, there have been studied and developed various runflat tires and safety tires that are capable of continuously running in uninflated conditions over a considerable distance until reaching facilities for repair and mend even when the pneumatic tires are punctured. For example, there are known a runflat tire having an improved tube such as reinforced tube, multi-chamber tube, filled tube and folded tube, a sealant-coated tire, a sealant-filled tire, a core built-in type tire, etc. Recently, Japanese Patent Application Laid-Open No. 7-276931 discloses a doubly structured safety tire comprising an external tire and an internal tire slightly smaller than the external tire which is disposed inside the external tire.
However, these conventional tires are difficult to produce because a specific production process and auxiliary members made of specific materials are required. In addition, the tires are difficult to be fit to wheel rim and be handled. For example, the tube-improved runflat tire having a multi-chamber tube is impractical because of difficulty in producing the tube. The sealant-coated tire or a sealant-filled tire have difficulty in developing filling methods of sealant and sealant materials. The core built-in type tire is difficult to fit its core to rim. The safety tires of mousse type such as sponge-filled tires and elastomer-filled tires are difficult to produce, and the shape thereof is difficult to control and stabilize. The safety tire disclosed in Japanese Patent Application Laid-Open No. 7-276931 are heavy in weight because of its double structure, resulting in deteriorated fuel consumption.